We require the PSN Backup Codes so we can log in without using one of the temporary codes that are being sent to you when 2-Step Verification is turned on. That way the booster can log in to your account without depending on each other's availability to receive the code.

So, how to do it? You must turn on 2-Step Verification in order to get the backup codes.

Here's how to do it on all available platforms: